import math


class Circle:
    def __init__(self, r):
        self.r = r

    def get_area(self):
        return 3.14 * pow(self.r, 2)

    def get_perimeter(self):
        return 2 * 3.14 * self.r


circle = Circle(2)
print("面积：", circle.get_area())
print("周长:", circle.get_perimeter())

r = eval(input("请输入圆的半径:"))

circle = Circle(r)

print("半径", r, "面积：", circle.get_area())
print("半径", r, "周长:", circle.get_perimeter())
